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New Canine Cancer Vaccine Offers Hope

The Big ‘C’ in canines: New options for our four-legged friends ...

We who share our lives with our furry four-legged friends are too often devastated to find out that our beloved companions, dogs, often suffer from cancer just as we humans do. 

In fact, it is estimated that cancer is now the leading cause of death in pet dogs. While this statistic may sound grim, with the many advances in modern veterinary medicine and pet foods, our dogs are living longer and lead healthier lives in general. But with a longer lifespan, we are seeing an increase of dogs suffering from cancer too.

Dogs have evolved alongside humans for thousands for years. They are exposed to the same environment and similar chemicals and nutrition. Dogs also develop cancer very similarly to their owners, often presenting with later stage disease as unlike humans they can’t say to their owners “I’m not feeling that flash” and get diagnosed early. There is a lot of overlap between human and canine cancer with melanoma, lymphoma and bone cancer common in both species.

The options available to treat cancer in our dogs are often not the same or as extensive as those available to people. Primary treatments like in humans is surgery and - depending on the type of cancer - chemotherapy and/or radiotherapy. The cost associated with chemo and radiotherapy, often means surgery is the only option for some dog owners.

What is Immunotherapy and how is it used to treat Cancer?

You may have heard of a new cancer treatment in humans called ‘Immunotherapy’. Immunotherapy involves stimulating or manipulating a patient’s own immune system to help fight against their cancer. 

There are different types of immunotherapies available to humans including antibodies called ‘checkpoint inhibitors’. These stop cancer cells from shutting down the immune system. Car-T cells which are T cells taken from a patient, are modified to recognise the cancer and then put back into the patient as a therapy which is effective in blood cancers
Weir, C, et al. 2018, 'The Safety of an Adjuvanted Autologous Cancer Vaccine Platform in Canine Cancer Patients
Veterinary Sciences. vol.5, no.4, pp.87
Another form of immunotherapy is cancer vaccines whereby tumour proteins or antigens (often a patient’s own) are incorporated into a vaccine to help the patient’s immune system fight back against the cancer.

Dr Chris Weir is a researcher at the Northern Blood Research Centre at the Kolling institute, which is part of the University of Sydney. For over a decade he has worked on immunotherapies, particularly cancer vaccines. It was by a chance meeting that his work began to be used to treat dogs

 “I was on an animal ethics committee and one of the vets on the committee found out what I did, and we then began treating dogs with cancer” Dr Weir said. Fast forward ten years with lots more research and testing and the next generation of personalised cancer vaccine is here

Dr Weir preparing the vaccine
“The early vaccines we developed were pretty crude, but we learnt a lot along the way’. It was by another lucky contact that a new collaboration started. 

One of the key aspects to making a cancer vaccine is the adjuvant which is substance the tumour proteins are put into to make up the vaccine. “There are lots of different kinds of adjuvants which all stimulate the immune system in different ways. If you use the wrong one basically the vaccine won’t work” Dr Weir said. 

Searching for a better adjuvant Dr Weir met Professor Nikolai Petrovsky, medical doctor and researcher, vaccine and adjuvant guru at Flinders University who became interested in the work and the two have collaborated ever since. “Nik (Professor Petrovsky) gave me access to all these innovative adjuvants and after lots of testing we found one that worked”. 

After showing the vaccine could slow tumour growth in several aggressive models of cancer (Brain, Pancreatic, Lung) and that the vaccine worked alongside chemotherapy and other immune therapies a new trial was started in dogs.

As part of a collaboration between Sydney University Veterinary Teaching Hospital with Oncologists Dr Peter Bennett and Dr Katrina Cheng and researchers at the University of Queensland School of Veterinary Science, Associate Professor Rachel Allavena and Dr Annika Oksa-Walker since 2017 a safety study with the vaccine has been ongoing. 
(from Left to Right): Daisy, Rocco, Ralph and Shiraz - some of the canine cancer patients [1] who took part in the trial
Over 150 dogs with over 16 different types of cancer have been treated with a vaccine made from their own tumour. The vaccine has been provided at no cost to the owner and has been used as a monotherapy or alongside chemotherapy

“The main aim was to show the vaccine was safe to use in a wide range of cancers” Dr Weir said. After 2 years and over 500 doses administered there have been no safety concerns and there is evidence that the vaccine is effective in cancers such as lymphoma, mast cell tumours, squamous cell carcinoma and a variety of sarcomas. 

“While the vaccine hasn’t worked for some cancers or patient’s we have had some incredible results and happy dog owners” Dr Weir said. The results of the initial cohort of dogs treated with vaccine were published in Veterinary Sciences Journal in late 2018. You can find the link here.

The next step for the vaccine is to do trials in the cancer types that have the best response. Funding for canine cancer trials is limited though. “We have had great support from organisations like the Canine Research Foundation but to do these next trials we need a lot more funding” Dr Weir commented. 

To try and achieve this goal, he set up a crowd funding page through the University of Sydney which to date has raised close to $30,000 towards the research. “It’s a good start but the more we raise the more dogs we can potentially help” Dr Weir said. They have also applied for funding in the USA from bodies such as canine health foundation (CHF) which provide bigger grants for canine studies. If funded, these trials will be performed in the USA. 

“I’d love to do a trial here in Australia, but unless we raise the funds ourselves it may not happen” Dr Weir said.

Griffin's Story

Dr Annika Oksa-Walker is a vet who under the supervision of Associate Professor Rachel Allavena has been doing a PhD on the vaccine in dogs with cancer. She has done everything involved in their treatment from surgery, to processing the tumour into personalised vaccines, administration, care and most importantly monitoring blood and what is going on in the tumour for signs of response. 

PhD Candidate Dr Annika Oksa
with
 Griffin, one of the patients in the trial
One of Dr Oksa-Walker’s star patients is a bouncy Rottweiler called Griffin. Griffin was given a poor prognosis of only 3 months to live (with chemotherapy) after developing a highly aggressive cancer called a T cell lymphoma

Despite a major surgery, the cancer had come back and was invading large portions of the skin on his side and chest. After receiving the vaccine Griffin’s cancer has disappeared, and now 18 months later, he is happy and healthy enjoying life with his family. 

Dr Oksa-Walker notes “one of the greatest things about being a veterinarian doing research is taking new treatments and curing patients that have no other option. In Griffin’s case his family couldn’t use chemotherapy because they had a young daughter. So it was fantastic that the vaccine cured him by itself”. 

The team are working to understand more about how the vaccines work so they can improve the treatments and cure more dogs. 

Written by Dr. Christopher Weir (Northern Blood Research Centre at the Kolling institute) for Australian Dog Lover, September 2019

Help support the University of Sydney's visionary research which aims to better treat canines suffering from cancer.

Your donation will help the development of new canine cancer therapies for dogs at the University of Sydney, which could further develop future human cancer treatments.
https://crowdfunding.sydney.edu.au/project/11839

[1] Photo: Some of the cancer patients who benefited from the canine vaccine trial

  1. Daisy: Lymphoma – Nearly 2 years in remission (Vaccine only)
  2. Rocco: Lymphoma – Chemotherapy + Vaccine
  3. Ralph:  Anal sac carcinoma –  Chemotherapy + Vaccine + Radiotherapy
  4. Shiraz:  Recurring Mast cell tumour post surgery
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